1.a)(2x-5)^2-3x^2=(x+2)^2-3
4x^2-20+25-3x^2=x^2+4x+4-3
x^2-20x+25=x^2+4x+1
-20+25=4x+1
-20x-4x=1-25
-24x=-24
x=1
б)(2x-1)(x+1)-x^2=(x-3)^2-10
2x^2+2x+x-1+x^2=x^2-6x+9-10
x^2+x-1=x^2-6x-1
x=-6x
x+6x=0
7x=0
x=0
5)a)(3x-1)^2
Б)(4x+1)^2
в)36x^2+84xy+49y^2=(6x+7y)^2
г)?
д)?